With development of electronic technology, not only rigorous demands are proposed on the appearance and the quality of electronic products, but also higher attention has been paid to price and practicability of the electronic products.
In order to meet public requirements, SOG (System on Glass) technology has been widely applied in the existing electronic products. SOG refers to integrating driving circuit and system circuit on an array substrate, and appearance of such technology has provided great convenience to manufacture and design of electronic product. The manufacture cost of the electronic products is greatly reduced since developers only need to perform simulation on the system circuit based on TFT and then can implement the circuit through a certain process. In addition, the products can also be greatly miniaturized by adopting highly integrated circuit design.
Especially for a display panel, SOG can integrate a driving system comprising a gate driver, a data driver, a multiplexer (Mux), a DC-DC converter (DC-DC), an digital to analog converter (DAC), a timing sequence controller (TCON) and so on, such that cost can be reduced greatly, screen bezel can be minimized, and problems of voltage drop on resistor, noise, reliability and so on caused by mutual connection among different driving chips can be solved. In order to implement more system functions, the development of the SOG technology is in direction of much higher integration and much more miniaturization, and the development of the display has the tendency of low cost, energy saving, low weight and thin thickness. The SOG technology has became the inevitable trend of the development of the system circuit.
In the existing display panels, various models requiring to be driven by a ramp signal and comprising DA converter, AD converter and so on are comprised in array substrates. However, a ramp signal generator cannot be effectively integrated by adopting the current SOG technology, and a ramp signal generator additionally arranged will cause area of the driving circuits to be increased greatly, which has a restriction on the further miniaturization of the display apparatus. On the other hand, it is difficult for the existing ramp signal generator to generate a ramp signal output having good linearity, which may dramatically limit the quality of the display apparatus.